1. Field of the Invention
The present invention relates to a method and system for managing an energy variation of an aircraft provided with at least one propulsion system, capable of generating a thrust force on said aircraft comprised in a thrust range.
2. Description of the Related Art
In the aircrafts according to the state of the art, the pilot manages the aircraft's energy by acting on several controls, and in particular on the gas lever and the airbrake control. The gas lever allows the pilot to control the speed of the engine(s). In response to such a command, the thrust delivered by the engine(s) varies, during a transitional period, until it reaches a stabilized value, which depends in particular on the flight point of the aircraft.
Independently, the pilot can modify the drag undergone by the aircraft in particular by modifying the configuration of the airbrakes.
The aircraft's response to these commands is generally shown in the control cabin or cockpit using several information viewing devices.
In particular, the speed of the engines can be viewed using indications in percentage of the maximum rating in the system's authority, relative both to the current speed of the engines, and the speed ordered by the pilot.
This viewing alone does not allow the pilot to determine the aircraft's energy, and in particular the variation thereof.
Aircrafts are therefore generally provided with other viewing devices dedicated in particular to steering the aircraft. These devices can be of the head-down type, i.e. arranged on the aircraft's instrument panel, and/or the head-up type.
The head-up display preferably makes it possible to superimpose information to help with aircraft handling on the outside environment seen through the canopy of the aircraft. The main indications displayed are an artificial skyline, superimposed on the actual skyline, a model symbol of the aircraft, a speed vector symbol of the aircraft, the position of which relative to the skyline indicates the gradient of the aircraft, and a symbol in the form of a chevron indicating the acceleration rate of the aircraft. Thus, when the aircraft accelerates, the chevron is above the speed vector symbol of the aircraft, and when it decelerates, the chevron is below the speed vector symbol of the aircraft.
The head-down display makes it possible to superimpose this same information for helping with aircraft handling on a virtual representation of the outside world or on a simplified representation of the world in the form of a brown uniform background for land and a blue uniform background for the sky.
These representations allow the pilot to estimate the gradient of the aircraft and its acceleration rate, in response to a rating command. However, when the pilot acts on the gas lever and/or the airbrakes, he can only view the result of his command in terms of acceleration and gradient once the rating is stabilized. Thus, the pilot must generally make changes to the control of the rating to achieve the desired acceleration and gradient.
Moreover, the pilot himself must interpret the indications in percentage of the rating to deduce the possible variation field in terms of acceleration and gradient, relative to his current flight point.
This control method and this type of display impose a heavy workload on the pilot, and can be a source of errors, due in particular to the amount of information that must be analyzed by the pilot and the difficulty of interpreting it in terms of energy.